Type-Based XML Projection

10 years 11 months ago
Type-Based XML Projection
XML data projection (or pruning) is one of the main optimization techniques recently adopted in the context of main-memory XML query-engines. The underlying idea is quite simple: given a query Q over a document D, the subtrees of D not necessary to evaluate Q are pruned, thus obtaining a smaller document D. Then Q is executed over D, hence avoiding to allocate and process nodes that will never be reached by navigational specifications in Q. In this article, we propose a new approach, based on types, that greatly improves current solutions. Besides providing comparable or greater precision and far lesser pruning overhead our solution, unlike current approaches, takes into account backward axes, predicates, and can be applied to multiple queries rather than just to single ones. A side contribution is a new type system for XPath able to handle backward axes, which we devise in order to apply our solution. The soundness of our approach is formally proved. Furthermore, we prove that the ap...
Véronique Benzaken, Giuseppe Castagna, Dari
Added 30 Oct 2010
Updated 30 Oct 2010
Type Conference
Year 2006
Where BDA
Authors Véronique Benzaken, Giuseppe Castagna, Dario Colazzo, Kim Nguyen
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